Rolls-Royce and Airbus are just about to start flight-testing the 84,000-pound-thrust Trent XWB engine for the A350XWB. Airbus’s A380 flying testbed (MSN 001) has already been fitted with the test engine and requisite instrumentation and is only waiting “for the weather in Europe to warm up a bit,” according to Rolls-Royce chief operating officer Mike Terrett.
The engine has been installed on a dedicated pylon in the number-three position (inboard right wing), and the trial program is being conducted jointly by Airbus and Rolls-Royce. “We both want to test things, such as the nacelle, which Airbus is responsible for,” noted Terrett.
From the engine manufacturer’s standpoint, altitudes can be simulated in a static testbed on the ground, but aircraft movements can’t easily be replicated and this make flight trials a necessity early on. The first test sortie will therefore be taking place roughly one year before the A350’s maiden flight. “We’ll learn a lot, so that we’ll be comfortable with the engines that will actually go on to the A350,” said Terrett. The engine, which is equipped with the largest fan ever on a Trent engine (at 118 inches), was installed on the aircraft in October last year.
Overall, Rolls-Royce now has eight Trent XWBs in various stages of testing. Program director Chris Young said that his team is busily building hours and cycles to prove the full capability of the new turbofan ahead of in-service tests.
“We are not changing our test program despite the change in timing at Airbus [for A350XWB certification],” he told a pre-show briefing, referring to the European airframer’s admission in November that the program has had to be delayed with a view to achieving first flight in the first half of 2013. “We can achieve a more mature entry into service with lower risk. We didn’t need the extra time but we will make good use of it.” Rolls expects to complete certification for the -800 and -900 versions of the Trent XWB by the end of 2012.
Meanwhile, work also is continuing for the Trent XWB that would power the larger A350-1000 aircraft. The planned power rating for this engine has been increased from 93,000 pounds to 97,000 pounds.
Again, Rolls is taking the time available while Airbus mulls the timeline for the -1000 program to reduce technology risk. For instance, Young explained that the company has already been able to prove the clearances and cooling configurations for the shroudless blades. Detailed engineering work will continue through 2013 and the first test engine for the -1000 will be built in the first quarter of 2014.